1. Field of the invention
The invention relates to a puncture closure for closing a puncture of a blood vessel, particularly of an artery, a vein short circuited with an artery, a shunt or a prosthesis and the like being under arterial pressure, this puncture closure has a pressure chamber, which can be loaded with excess pressure, as well as an opening for receiving the pressure medium and can be fastened onto the body in the vicinity of the puncture, whereas the body facing part of the pressure chamber is extensible.
Blood vessels within the scope of the present invention are all arterial vessels, i.e. all vessels leading away from the heart or vessels being under arterial pressure (133,322-266,644 mbar). Thus veins short circuited with an artery, and prosthesis connected to arteries (interpositions or shunts) fall within this denomination, since with all these vessels the problem of closing the wound after medical intervention occurs.
In many invasive interventions in human and animal bodies the physician needs to gain access to an artery or an arterial vessel. Such invasive interventions are for example catheter examinations of any kind, like arteriographies at the heart, in the brain and so on by means of X-ray (roentgen) contrast medium injected into an artery; balloon dilatations or millings of arteries; thrombectomies; functional examinations of the left heart or bringing drugs to defined blood irrigated areas, like for example to the coronary arteries for lysis.
Patients undergoing chronic hemodialysis are equally concerned, since, in order to clean the blood outside the body, an easily accessible arterialized vessel has been operatively provided. For example, this vessel can be a vein of the patient itself or an inserted plastic tube short circuited with the artery (shunt).
After each blood cleansing procedure, that means several times a week the same problem occurs, since the aspirated shunt is difficult to close.
The blood is pressed with a pressure of 133,322-266,644 mbar through the puncture of the vascular wall into the open air or into the tissue surrounding the artery. Due to the relatively high pressure in the artery, a lot of blood gets lost in a very short period of time and undesirable hematomae can arise in the surrounding tissues.
Loss of blood and hematomae are absolutely to be avoided. Up to now this has been achieved by exerting an adequate pressure onto the artery or the arterial vessel with the finger.
This pressure can be adjusted individually according to the blood pressure in the vessel and to the depth and consistency of the covering tissue. It varies interindividually (from one patient to another) and intraindividually (depending on changes in the blood pressure, especially on dropping of the blood pressure of one specific patient) and has to be continuously controlled and adjusted.
If the pressure exerted is to weak, a hematomae of considerable dimensions having several liters can occur, may cause serious consequences. A few consequences which have to be avoided are quoted below by way of example: hemodynamic difficulties, i.e. blood circulation problems occuring when the remaining, intravascular blood volume cannot compensate the blood loss any more; compartment syndromes, i.e. compression of important structures (nerves, shunt) by the hematoma (or by the pressure of an additionally developing edema), the compression destroying these structures; local sterile inflammatory responses during resorption and organization (tissue reconstruction) of the hematoma; infection of the hematoma; and possibly the necessity to remove operatively the hematoma with further risks like infection, abscess, secondary wound healing, and so on.
On the other hand, the exerted pressure should not be too strong, since in that case, the blood vessel would completely collapse. Possible consequences of a too strong pressure are disturbances of the blood supply in subsequent structures (e.g. in a leg and so on) with its possible irreversible loss due to the ischemic tissue damage or, particularly with dialysis patients, shunt occlusion due to thrombogenesis following hemostasis.
2. Description of Related Art including information Disclosed Under 37 CFR .sctn. 1.97-1.99
Due to the serious complications involved, inaccurate systems of puncture closure like clamps or circular tourniquets and so on could not find acceptance. The same applies to the puncture closures proposed in the EP 0 554 602 and EP 0 514 026. These puncture closures have a pressure chamber fastened onto the body by means of a surrounding tape and inflated with air pressure. The expansion of the pressure chamber generates a pressure onto the tissue surrounding the puncture closure. Herewith the manually exerted pressure is simply replaced by a pressure bandage, whereas the above mentioned problems of an accurate adjustment to the momentaneous situation still remain.
That is why the pressure is still exerted with the finger, since, thanks to the tactile sense, pressure can be individually varied and adjusted.
But often the patient is not able to exert this pressure with his finger. A debilitation within the frame of the basic disease, a sedation because of the completed examination or the lack of experience are making it impossible for the patient to execute by himself the above mentioned activity.
This means that the nursing or the medical staff has to take on the job of doing it, so that a considerable period of time, namely between 10 and 60 minutes, is blocked for this activity.
This requires a lot of time from the nursing and the medical staff and for the bearer it is expensive and inefficient. Moreover, the above mentioned complications prove that the best solution used up to now is not yet good enough.